Cleanup include structure, constexpr and noexcept compiler workarounds.

* Nest "gsl" directory inside a new "include" directory.

* Cleanup the _MSC_VER conditionals a bit; use constexpr on VS2017+.

* Don't #define noexcept on non-Microsoft implementations.

* Workaround VS2017 bug in multi_span. (Also implement == and != for static_bounds_dynamic_range_t because I'm an EoP semantic soundness snob.)

Fixes #441.

1 files changed, 85 insertions, 0 deletions

diff --git a/include/gsl/gsl_assert b/include/gsl/gsl_assert
new file mode 100644
index 0000000..04f34b3
--- /dev/null
+++ b/include/gsl/gsl_assert
@@ -0,0 +1,85 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
+//
+// This code is licensed under the MIT License (MIT).
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#pragma once
+
+#ifndef GSL_CONTRACTS_H
+#define GSL_CONTRACTS_H
+
+#include <exception>
+#include <stdexcept>
+
+//
+// There are three configuration options for this GSL implementation's behavior
+// when pre/post conditions on the GSL types are violated:
+//
+// 1. GSL_TERMINATE_ON_CONTRACT_VIOLATION: std::terminate will be called (default)
+// 2. GSL_THROW_ON_CONTRACT_VIOLATION: a gsl::fail_fast exception will be thrown
+// 3. GSL_UNENFORCED_ON_CONTRACT_VIOLATION: nothing happens
+//
+#if !(defined(GSL_THROW_ON_CONTRACT_VIOLATION) || defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) ||    \
+      defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION))
+#define GSL_TERMINATE_ON_CONTRACT_VIOLATION
+#endif
+
+#define GSL_STRINGIFY_DETAIL(x) #x
+#define GSL_STRINGIFY(x) GSL_STRINGIFY_DETAIL(x)
+
+#if defined(__clang__) || defined(__GNUC__)
+#define GSL_LIKELY(x) __builtin_expect (!!(x), 1)
+#define GSL_UNLIKELY(x) __builtin_expect (!!(x), 0)
+#else
+#define GSL_LIKELY(x) (x)
+#define GSL_UNLIKELY(x) (x)
+#endif
+
+//
+// GSL.assert: assertions
+//
+
+namespace gsl
+{
+struct fail_fast : public std::runtime_error
+{
+    explicit fail_fast(char const* const message) : std::runtime_error(message) {}
+};
+}
+
+#if defined(GSL_THROW_ON_CONTRACT_VIOLATION)
+
+#define Expects(cond)                                                                              \
+    if (GSL_UNLIKELY(!(cond)))                                                                     \
+        throw gsl::fail_fast("GSL: Precondition failure at " __FILE__ ": " GSL_STRINGIFY(__LINE__));
+#define Ensures(cond)                                                                              \
+    if (GSL_UNLIKELY(!(cond)))                                                                     \
+        throw gsl::fail_fast("GSL: Postcondition failure at " __FILE__                             \
+                             ": " GSL_STRINGIFY(__LINE__));
+
+#elif defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION)
+
+#define Expects(cond)                                                                              \
+    if (GSL_UNLIKELY(!(cond))) std::terminate();
+#define Ensures(cond)                                                                              \
+    if (GSL_UNLIKELY(!(cond))) std::terminate();
+
+#elif defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION)
+
+#define Expects(cond)
+#define Ensures(cond)
+
+#endif
+
+#endif // GSL_CONTRACTS_H